Many packaging containers filled with various fluids are sealed with a variety of types of leak-proof, freshness (e.g., hermetic), tamper-resistant, and/or tamper-evident devices. One common type of sealing method for paper-product cartons filled with diary, juice, and/or other liquids employs a plastic spout having an integral seal with a pull-tab (and/or ring). While such integral pull-tab or pull-ring seals provide advantages over other sealing systems, they are subject to various deficiencies.